Pyrolysis of dewatered sewage sludge, or mixtures of organic solid wastes, and sewage sludge, can be a self-sustaining process. The major useful products are char, fuel oils, and noncondensable gases such as methane, hydrogen, and carbon monoxide. The yield is dependent on the pyrolyzing temperature, residence time, composition of wastes, and moisture contents. Major advantages are significant—volume reduction, innocuous end products, and energy recovery.